<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>

</body>
<script>
    // var arr = [2,5,9,3,6,1];
    // var x = Math.max(arr[0],arr[1]);
    // console.log(x);


    // var arr = [12,3,4];
    // var obj = {};
    // console.log(arr instanceof Array);
    // console.log(obj instanceof Array);
    // console.log(Array.isArray(arr));
    // console.log(Array.isArray(obj));

    var numList = [];
    var maxList = [];
    var minList = [];
    var characters = ["_", "!", "$"];
    for (var i = 48; i <= 57; i++) {
        var char = String.fromCharCode(i); //根据编码返回对应的字符
        numList.push(char);
    }
    for (var i = 65; i <= 90; i++) {
        var char = String.fromCharCode(i); //根据编码返回对应的字符
        maxList.push(char);
    }
    for (var i = 97; i <= 122; i++) {
        var char = String.fromCharCode(i); //根据编码返回对应的字符
        minList.push(char);
    }
    var chars = numList.concat(maxList, minList, characters);
    console.log(numList, maxList, minList, characters, chars);
</script>

</html>